Fasciola Hepatica Eggs Research Articles

Lethal effect of high temperatures on the eggs of Fasciola hepatica

39.9%, respectively, and these values in the group incubated at 45°C were 46%, 42.5% and 33.7%, as well. However, in the case of incubation at 50°C for 1, 2, 3, 4 and 5 h, these values were recorded as 1.96%, 0.57%, 0.07%, 0.00% and 0.00%, respectively. The results indicated that the eggs were susceptible to high temperatures and incubation of the eggs at 50°C for 4 h was enough to significantly inactivate the eggs and prevent miracidial formation (P<0.001). However, using the livestock faeces as fertilizer in many rural areas may lead to the contamination of pasture. According to the findings of this study, in the areas with a high prevalence rate of Fasciola hepatica, manure storage for a sufficient time or heating the livestock manure before use as fertilizer is strongly recommended.

Fasciola hepatica: Comparison of the sedimentation and FLOTAC techniques for the detection and quantification of faecal egg counts in rats

We compared the sedimentation and FLOTAC techniques for the detection and quantification of Fasciola hepatica eggs in faecal samples obtained from 120 experimentally-infected rats before intervention, and in 42 rats after drug administration. Additionally, the average time for a single test was determined. A single FLOTAC showed a higher sensitivity (92.6%) than 2, 4 and 8 sedimentation readings (63.0–85.2%) for detecting F. hepatica eggs in rat faeces post-treatment. On average, it took 21 min to prepare and examine a single FLOTAC, whereas 114 min were needed for the sedimentation method including the reading of 8 slides. In both treated and untreated rats, the sedimentation method resulted in higher mean faecal egg counts (FECs) than FLOTAC ( P < 0.05). In view of the high sensitivity and efficiency, the FLOTAC technique holds promise for experimental work in the F. hepatica-rat model. Additional research is needed to determine the reasons for the observed differences in FECs.

Seroepidemiology of Fasciola Hepatica in Mersin province and surrounding towns and the role of family history of the Fascioliasis in the transmission of the parasite

Fascioliasis is an important zoonotic disease caused by Fasciola hepatica. This zoonosis may cause serious morbidity and a considerable financial burden. Knowledge about Fasciola hepatica and interest in this parasite have increased in Turkey recently. However, there have been few studies on the real prevalence of this condition in the country. Therefore, we aimed to determine the prevalence of fascioliasis and the role of family history of the condition in the transmission of the parasite in the province of Mersin. Taking account of their populations, 729 people without a family history of fascioliasis and 155 people with a family history of fascioliasis from the city of Mersin and randomly selected three towns were included into the study to obtain a sample that well represented the population of the province of Mersin. A questionnaire composed of items about consumption of green leafy vegetables, stock-breeding and clinical symptoms of the disease was used to collect data. Excretory/ secretory (ES)-ELISA was used to detect IgG antibodies to Fasciola hepatica. People seropositive for Fasciola hepatica underwent abdominal ultrasonography, physical examination, biochemistry, and stool tests for the detection of Fasciola hepatica eggs. A total of 0.79% of the participants were seropositive for Fasciola hepatica. One point ninety-three percent of the individuals with a family history of fascioliasis and 0.55% of the individuals without a family history of fascioliasis were seropositive for Fasciola hepatica. Out of 7 individuals found to be seropositive for Fasciola hepatica, 5 were female, 2 were male, and 4 had a family history of fascioliasis. Five and 4 patients, respectively, had a history of consuming green leafy vegetables and 4 had a history of stock-breeding. The clinical evaluation revealed that 4 patients had at least one sign of fascioliasis. Three patients had signs of fascioliasis on ultrasonography and 1 had Fasciola hepatica egg in stool examination. There was no significant difference in seropositivity for Fasciola hepatica between the individuals with and without a family history of fascioliasis (x2: 0.077, p>0.05). The prevalence of fascioliasis was hypoendemic in the province of Mersin. There were no significant differences in the Fasciola hepatica prevalence between the groups with and without family history of fascioliasis. However, studies with larger sample sizes may reveal a difference.

Comparative assessment of albendazole and triclabendazole ovicidal activity on Fasciola hepatica eggs

The benzimidazole compounds albendazole (ABZ) and triclabendazole (TCBZ) are both effective against Fasciola hepatica, although ABZ is only effective against adult flukes. Additionally, ABZ is a broad-spectrum nematodicidal compound with well-known ovicidal activity. However, no data on the ovicidal effect of TCBZ against F. hepatica eggs are available. The work reported here evaluated the comparative ovicidal effect of ABZ, TCBZ and their sulphoxide metabolites on F. hepatica eggs recovered from bile of sheep artificially infected with either a TCBZ-susceptible (Cullompton) or a TCBZ-resistant (Sligo) isolate of F. hepatica. Additionally, the effects of different non-flukicidal methylcarbamate benzimidazole compounds on the hatching of F. hepatica eggs were evaluated. Eggs (500 eggs/mL, n = 4) were incubated for 12 h either with TCBZ, TCBZ sulphoxide (TCBZ.SO), ABZ (5, 10 and 20 nmol/mL) or without drug (untreated control) (Experiment 1). Additionally, the effect of TCBZ and TCBZ.SO (5 nmol/mL) on egg hatchability was examined after a long (15 days) drug exposure (Experiment 2). Furthermore, the ovicidal effect of ABZ and ABZ.SO at different concentrations (5, 1, 0.5, 0.1and 0.05 nmol/mL) (Experiment 3), and the effect of fenbendazole (FBZ), oxfendazole (OFZ), mebendazole (MBZ), flubendazole (FLBZ) (5 nmol/mL) and reduced-FLBZ (R-FLBZ) (2 μg/mL) on fluke eggs, were evaluated after a 12-h exposure (Experiment 4). Egg hatch was assessed by direct microscopic observation after incubation at 25 °C for 15 days. TCBZ and TCBZ.SO did not affect egg hatch after a 12-h incubation. A similar result was obtained after a much longer drug exposure (15 days) (Experiment 1 and 2). However, a significant ( P < 0.05) inhibition of egg hatch was observed in ABZ- and ABZ.SO-incubated eggs (Experiments 1 and 3). Additionally, the non-flukicidal compounds (Experiment 4) affected egg hatchability, particularly FLBZ and R-FLBZ. In conclusion, ABZ and ABZ.SO had a clear inhibitory effect on egg development of F. hepatica. However, the most extensively used flukicidal compound, TCBZ, and its main sulphoxide metabolite, did not affect egg hatch, even in TCBZ-susceptible flukes.

Presence of Fasciola hepatica in Feral Nutria (Myocastor coypus) Living in a Public Park in Brazil

Sixteen nutria (Myocastor coypus) from a protected area in Curitiba, Brazil, were sampled to determine the prevalence of Fasciola hepatica eggs and intestinal parasites and the presence of snails in the habitat used by nutria. The overall prevalence rates were 56.25% (9) for F. hepatica eggs, 87.50% (14) for cestode eggs, 56.25% (9) for ascarid eggs, 50% (8) for coccidian (Eimeriidae) oocysts, and 56.25% (9) for Strongyloidea eggs. Fasciola hepatica eggs had an average size of 138 microm x 72 microm. The following mollusks were found: Physa cubensis, Physa marmorata, and Biomphalaria tenagophyla. These results suggest that the infected nutria could serve as a source of contamination for other animals, humans, and surface water. This is the first report about parasites in nutria in the state of Paraná, Brazil.

Cervical tumor caused by the sexually mature stage of Fasciola hepatica

A 58-year-old man presented with an asymptomatic 5cm left anterior cervical tumor that had been present for over a year. Histological analysis revealed chronic inflammation and granuloma with giant cells surrounding Fasciola hepatica eggs. Fas2 antigen was detected in the tissue by immunohistochemistry. Serology for F. hepatica was positive, but stool examinations were negative and eosinophil count was normal. A month later, the tumor recurred, and an adult parasite was found during excision. The patient received triclabendazole, and after 6 months serology was negative. Erratic localization of F. hepatica reveals a pathology involving chronic inflammation caused by a sexually mature parasite, although according to theory only immature parasites are located in ectopic lesions.

Purification and removal of Ascaris and Fasciola hepatica eggs from drinking water using roughing filters

The performance of a horizontal roughing filter (HRF) and a downflow roughing filter (DRF) in the removal of Ascaris and Fasciola hepatica eggs was investigated. The experiments were performed at three filtration rates of 0.5, 1.0 and 1.5 m/h and different influent concentrations of Ascaris and Fasciola hepatica eggs. Alteration of the filtration rate in the range of 0.5–1.5 m/h did not have significant influence on the effectiveness of the roughing filters. The HRF had higher efficiency in the removal of both Fasciola hepatica and Ascaris eggs in comparison with the DRF, so that the average efficiencies of the HRF for the removal of Fasciola hepatica and Ascaris eggs at filtration rate of 1.0 m/h were determined to be 89.0 and 57.3%, respectively, whereas the same values of the DRF were 77.2 and 52.5%, respectively. The straining was confirmed to be the main mechanism of helminth eggs removal by the roughing filters, because Fasciola hepatica eggs with larger size were removed more effectively than Ascaris eggs. The results of this study indicate that the roughing filters, especially the HRF, had promising performance in the removal of helminth eggs and could be used for water and secondary effluent treatment.

In vitro evaluation of the action of the nematophagous fungi Duddingtonia flagrans, Monacrosporium sinense and Pochonia chlamydosporia on Fasciola hepatica eggs

This work evaluated the in vitro action of four isolates of the nematophagous fungi Duddingtonia flagrans (AC001), Monacrosporium sinense (SF53) and Pochonia chlamydosporia (VC1 and VC4) on eggs of Fasciola hepatica. The eggs were plated on 2% water-agar with the grown isolates and control without fungus. After 7, 14 and 21 days, the eggs were removed and classified according to the following parameters: effect type 1, lytic effect with no morphological damage to eggshells; type 2, lytic effect with morphological changes in eggshells and embryos; and type 3, lytic effect with morphological changes in embryos and eggshells, with hyphal penetration and internal egg colonization. Pochonia chlamydosporia showed ovicidal activity on F. hepatica eggs in the studied intervals of the type-3 effect, of 12.8% (VC1) and 16.5% (VC4); 14.4% (VC1) and 18.7% (VC4), 20.1% (VC1) and 21.5 % (VC4), over 7, 14 and 21 days respectively. No statistical difference was found (P > 0.01) among the isolates VC1 and VC4 for effects type 1, 2 and 3 during the studied intervals. Duddingtonia flagrans (AC001) and Monacrosporium sinense fungi only showed effect type 1, with no significant difference between them, with the following results: 60.1% (AC001) and 57.5% (SF53); 62.3% (AC001) and 62.0% (SF53); 66.5% (AC001) and 73.4% (SF53), over 7, 14 and 21 days respectively. Pochonia chlamydosporia fungi negatively influenced the in vitro F. hepatica viability. Therefore it can be considered as a potential biological control agent for this helminth.

La prévalence des helminthoses bovines a-t-elle été modifiée par la canicule de l’été 2003 dans le sud-ouest de la France ?

The heat wave of 2003 summer had serious consequences on helminths prevalence and epidemiology. Comparison of 1917 cattle epg counts in southwestern France for years before and after showed that prevalence and mean numbers of Fasciola hepatica, paramphistomids, Dicroccelium lanceolatum and gastrointestinal strongyles eggs were significantly reduced. Nevertheless, the next year the epg counts were quickly increasing. Several factors may have induced a more or less long modification: strains of helminths may become adapted, a new spreading of intermediate hosts may occur with a modified ecology and finally moving of hosts and reservoirs may be amongst causes of epidemiological changes. Finally, after a heat wave the anthelmintic pressure may be maintained, as parasites seem quickly become adapted to a novel and modified environment.

Chronic fascioliasis in farmed and wild greater rheas ( Rhea americana)

From 50 farmed Rhea americana slaughtered for human consumption, adult forms and eggs of Fasciola hepatica were found in 4. The other three livers were free of flukes but did show lesions caused by larval fluke migration. Histological lesions were similar to those caused by flukes in cattle and sheep. The rheas were from an endemic area of ruminant fascioliasis in Southern Brazil. F. hepatica eggs were also found in faecal samples of wild rheas from another endemic area in Southern Brazil. It is likely that the rheas play a role in the transmission of the disease to ruminants and could be jeopardizing the control of this parasitosis in endemic areas. From the best of our knowledge this is the first report of fascioliasis in R. americana.

Effect of a cysteine protease inhibitor on Fasciola hepatica (liver fluke) fecundity, egg viability, parasite burden, and size in experimentally infected sheep

Fasciola hepatica secretes proteolytic enzymes during liver invasion. The present study examined the effects of the cysteine protease inhibitor Ep-475 on sheep considering the following variables: serum levels of aspartate aminotransferase, L-lactate dehydrogenase, and gamma-glutamyltransferase, liver fluke fecundity, egg viability, parasite burden, and size. Twenty-four male sheep were randomly allocated in four groups of six animals each as follows: group A was infected with F. hepatica metacercariae and treated with 50 mg/kg of Ep-475, group B was infected and untreated, group C was uninfected and treated, and group D was uninfected and untreated. All animals were euthanized 10 weeks after the experimental infection. Serum activities of enzymes in infected animals were significantly lower in Ep-475-treated sheep than in untreated controls, although liver damage was produced. No significant reduction in total worm burden was observed between treated and untreated sheep. However, there was a significant difference on the average size, structure development, ova counts, and egg viability of liver flukes from these two groups. Results showed that Ep-475 reduces liver damage due to fasciolosis and induces an impairment of liver fluke growth and fecundity. These effects pinpoint liver fluke proteases as potential targets for pharmacological intervention.

Fascioliasis imported to Norway

We report 3 cases of fascioliasis imported to Norway: a 24-y-old male Vietnamese immigrant and a 51-y-old female Vietnamese immigrant with acute fascioliasis, and a 2-y-old male Ethiopian adoptee with chronic fascioliasis. Diagnosis was confirmed by detection of specific antibodies to Fasciola hepatica in the 2 first cases and by demonstration of Fasciola hepatica eggs in stool samples in the latter case. Treatment with oral triclabendazole led to prompt cure in all 3 patients. Imported fascioliasis is rarely reported but should be suspected in patients with a travel history to endemic areas, abdominal symptoms and hypereosinophilia of the blood.

Human fasciolosis in Van province, Turkey

This investigation was carried out to determine the frequency of the fasciolosis in Erciş, a town in the Van province located in the Eastern Turkey. The study includes 500 asymptomatic subjects (322 males and 178 females) whose ages ranged from 5 to 75 years. In all subjects, stool samples were examined at initiation of the study and one week later to rule out pseudoparasitosis. The methods of flotation (in saturated saline solution) and sedimentation (in formalin–ether solution) were used in examination of the stool samples. Fasciola hepatica eggs were detected in nine (1.8%) out of 500 subjects. In conclusion, our data showed that the prevalence of human fasciolosis was high in our region because watercress consumption was common. We also think that human fasciolosis is more frequent than expected in Turkey. To determine the exact prevalence of the disease, extensive serological investigations should be performed in different regions of Turkey.

Viabilidade de ovos de Fasciola hepatica de bovinos em sistema de biodigestão anaeróbia

Cattle Fasciola hepatica egg-viability was studied in closed system of anaerobic biodigestion. Two thirds of a biodigestor were filled with liquefied manure from eight Hosltein cows, naturally infected. For 10 consecutive weeks of observation, the biodigestor internal temperature ranged from 24oC to 28oC, and external temperature from 26oC to 33oC. All the effluent samples showed a constant pH of 7. The samples of the effluent were weekly collected, in a total of 10 and submitted to techniques to detect the presence and viability of the trematode eggs. It was detected a 42-day egg viability. Therefore, liquefied cattle manure containing Fasciola hepatica eggs must remain under anaerobic biodigestion for at least 42 days before its safe return to the environment.

Casos autóctones de Fasciola hepatica na região de Presidente Prudente, São Paulo, Brasil

O presente trabalho descreve, a partir da condenação de fígado de bovinos em matadouro, a ocorrência de fasciolose em uma propriedade na região de Presidente Prudente, São Paulo, com a confirmação de ovos de Fasciola hepatica em exame coproparasitológico e a presença de caramujos do gênero Lymnaea. Observou-se que a propriedade ofereceu condições favoráveis ao desenvolvimento do hospedeiro intermediário do parasito e ao surgimento de casos autóctones na região. A verificação desses casos deve servir de alerta para as potenciais perdas econômicas advindas desse tipo de parasitismo.

A contribution to the diagnosis of Capillaria hepatica infection by indirect immunofluorescence test.

A highly specific pattern of immunofluorescence was noted when sera from Capillaria hepatica-infected rats were tested against the homologous worms and eggs present either in paraffin or cryostat sections from mouse liver. The pattern was represented by a combined apple green fluorescence of the internal contents of worms and eggs, which persisted in serum-dilutions of 1:400 up to 1:1600. Unequivocal fluorescent pattern was observed from 15 days up to 3 months following inoculation of rats with embryonated C. hepatica eggs and such result was confirmed by the ELISA. After the 4th month of infection, the indirect immunofluorescence test turned negative, probably revealing the extinction of parasitism, however the ELISA was contradictory, disclosing high levels of antibodies in this period. The IIF was also negative when control normal rat sera and sera from rats administered by gavage with immature C. hepatica eggs (spurious infection), or for reactions made against Schistosoma mansoni eggs, although a weakly positive pattern occurred with Fasciola hepatica eggs. The indirect immunofluorescence test may be recommended for use with human sera to detect early C. hepatica infection in special clinical instances and in epidemiological surveys, since it is a simple, inexpensive, and reliable test, presenting excellent sensitivity and specificity. Although the diagnosis is positive only during early infection, this is the period when the symptoms are usually more severe and the need for differential diagnosis is greater.

The presence of Fasciola hepatica (Liver-fluke) in humans and cattle from a 4,500 Year old archaeological site in the Saale-Unstrut Valley, Germany

During an excavation of a site of the corded ware culture in the Saale-Unstrut-Valley (ca. 3000 BC) in Germany, a soil sample from the pelvis of a human skeleton was studied under palaeoparasitological aspects. Eggs of the trematode Fasciola hepatica and of the nematode genus Capillaria were found. This is the first case of a direct association of a F. hepatica-infestation to both a prehistoric human skeleton and domesticated animal remains. Sheep and cattle bones were present at the same site and F. hepatica eggs were found in bovine samples. This strongly points toward an existing infection cycle, involving humans as a final host.

Patterns in Size and Shedding of Fasciola hepatica Eggs by Naturally and Experimentally Infected Murid Rodents

Patterns in Size and Shedding of Fasciola hepatica Eggs by Naturally and Experimentally Infected Murid Rodents

Evaluation of a simple sedimentation method (modified McMaster) for diagnosis of bovine fascioliosis

A coprological sedimentation method is evaluated for quantification of egg shedding in bovine faeces. Through the inclusion of different number of Fasciola hepatica eggs in negative faeces, egg recovery rate and the sensitivity of the method were determined. The mean egg recovery rate of the technique was 76.72±15.42%. The sensitivity of the method was 33.3% whenever eggs/g of faeces (EPG) are less than 1.5 and 100% for higher values. To improve the diagnostic accuracy with this technique, it is advisable to increase the sample from 10 to 30 g of faeces when manipulating low egg shedding, which allowed for a sensitivity of 83.3%. Regression equations were calculated to quantify the relationship between the number of recovered and incorporated eggs.

Relationships between host species and morphometric patterns in Fasciola hepatica adults and eggs from the northern Bolivian Altiplano hyperendemic region

The highest prevalences and intensities of human fasciolosis by Fasciola hepatica are found in the northern Bolivian Altiplano, where sheep and cattle are the main reservoir host species and pigs and donkeys the secondary ones. Morphometric comparisons of many linear measurements, areas and ratios of F. hepatica adults (from sheep, cattle and pigs) and eggs (from sheep, cattle, pigs and donkeys) in natural liver fluke populations of the Bolivian Altiplano, as well as of F. hepatica adults and eggs experimentally obtained in Wistar rats infected with Altiplanic sheep, cattle and pig isolates, were made using computer image analysis and an allometric model. Although morphometric values of adult flukes from natural populations of sheep, cattle, and pigs showed great overlap, there were clear differences in allometric growth. The allometries analyzed were: body area (BA) versus body length (BL), BA versus body width (BW), BA versus perimeter (Pe), BA versus distance between posterior end of body and ventral sucker (P–VS), BL versus BW, BL versus Pe, and BL versus P–VS. These allometries show a good fit in the seven pairs of variables in all the populations examined. Comparative statistical analysis of the allometries shows that fluke adult populations from sheep, cattle and pigs significantly differ in BL versus BW and BL versus P–VS functions. Statistical analysis of F. hepatica egg size shows characteristic morphometric traits in each definitive host species. In experimentally infected rats, fluke adult allometry and egg morphometry do not vary depending on the Altiplanic definitive host species isolate. Our study reveals that the definitive host species decisively influences the size of F. hepatica adults and eggs, and these influences do not persist in a rodent definitive host model.